The present invention relates generally to a system for providing a support for mounting accessories to a generally cylindrical structure and, more particularly, to a system including a bracket which may be mounted to a wide range of structure diameters and which may be easily mounted to the structure without compromising the structural integrity of the structure.
There is a need for means to provide a mounting bracket on an existing structure, such as a vertically extending cylindrical structure, in order to support equipment or accessories which were not contemplated when the structure was erected. For example, cell towers comprising upwardly tapered, generally cylindrical structures, have been erected throughout the country to facilitate cellular phone usage. As usage of cellular phones and other electronic equipment increases, there is an increasing need for additional equipment and accessories, such as additional antennas and cables, to be placed on the cell towers. Alternatively, in some locations, there is a need to attach additional equipment or accessories to other elevated structures, such as attachment to the cylindrical legs of water towers and the like.
Various mechanisms for supporting the equipment and accessories have been proposed and typically include a support bracket which is attached to the vertical structure. In some instances, holes are drilled in the structure to permit bolts to be used to mount the brackets directly to the structure. However, the structural requirements of the structure are carefully engineered and provision of additional holes, particularly if a large number of brackets must be mounted to the structure, may structurally compromise the structure and therefore often requires reengineering to ensure that the additional holes do not jeopardize the strength of the structure.
In other instances, the brackets may be welded to the structure. Welding has its own limitations in that the welded surfaces must be clean in order to obtain a good weld, and the welding equipment is often heavy and bulky, which is not conducive to operations involving extreme heights.
A further method for supporting brackets on cylindrical structures involves providing a flexible clamping strap extending around the structure and having opposing ends attached to the bracket. For example, U.S. Pat. No. 1,432,561 shows a bracket which is held to a telephone pole by means of a chain wrapped around the pole and having ends tensioned at the bracket. U.S. Pat. No. 5,598,995 also shows a tensioned flexible member which forces a clamp assembly into contact with a cylindrical support to thereby hold the clamp assembly at a desired location.
The prior art devices incorporating flexible straps to hold clamp assemblies or brackets at a desired location on a structure are typically designed for a limited size diameter structure and are not designed for universal use on a wide range of structures. Further, it should be noted that on large structures, the frictional forces between the strap and structure are such that it is difficult to manually draw the strap to eliminate all slack in the strap prior to exerting a clamping force through the strap. As a result, it has been found that the mechanism for drawing the clamping force may not have enough travel to both take up the remaining slack in the strap and exert the required clamping force for holding the clamp assembly or bracket at the desired location.